A method for modifying 1,3,5-triazine derivatives characterized by heating and reacting a 1,3,5-triazine derivatives having at least one amino or mono-substituted amino group on a carbon atom or atoms on its ring with an alcohol in the presence of a metal catalyst and a hydrogen atom to introduce an alkyl group or an alkenyl group into each amino or mono-substituted amino group; another method for modifying 1,3,5-triazine derivatives characterized by heating and reacting a 1,3,5-triazine derivatives having at least one amino or mono-substituted amino group on a carbon atom or atoms on its ring with a dihydric alcohol in the presence of a metal catalyst and a hydrogen atom to introduce an alkyl group having a hydroxyl group into each amino or mono-substituted amino group; and 1,3,5-triazine derivatives obtained by the methods. The various modified sustituted 1,3,5-triazine derivatives thus produced are generally obtained as a mixture. These derivatives can be isolated as compounds having high-purity by a normal separation method for organic compounds, and the compounds are usable in the various applications mentioned in the specification.